On Sat, Apr 18, 2015 at 11:34:49AM +0200, Jan Kiszka wrote:
> On 2015-04-18 08:56, Maxime Ripard wrote:
> > On Thu, Apr 16, 2015 at 06:56:00PM +0200, Gilles Chanteperdrix wrote:
> >> On Thu, Apr 16, 2015 at 06:53:24PM +0200, Jan Kiszka wrote:
> >>> On 2015-04-16 18:43, Gilles Chanteperdrix wrote:
> >>>> On Thu, Apr 16, 2015 at 06:37:35PM +0200, Jan Kiszka wrote:
> >>>>> On 2015-04-16 18:16, Gilles Chanteperdrix wrote:
> >>>>>> On Fri, Apr 17, 2015 at 12:04:22AM +0800, GP Orcullo wrote:
> >>>>>>> On Thu, Apr 16, 2015 at 9:19 PM, Gilles Chanteperdrix
> >>>>>>> <[email protected]> wrote:
> >>>>>>>> On Thu, Apr 16, 2015 at 04:05:05PM +0800, GP Orcullo wrote:
> >>>>>>>>> Tested on a Cubieboard2 with v3.16.7-ckt9 kernel.
> >>>>>>>>
> >>>>>>>> Does not sunxi have GPIO ?
> >>>>>>>>
> >>>>>>>> --
> >>>>>>>>                                             Gilles.
> >>>>>>>
> >>>>>>> There's no GPIO driver in the mainline kernel. The original sunxi
> >>>>>>> kernel has incomplete support for GPIOs.
> >>>>>>
> >>>>>> Ok, what about timer and tsc? Basically, you should run through the
> >>>>>> ARM porting guide and check every modification to be made. And if
> >>>>>> you have done so, the commit message should mention it.
> >>>>>
> >>>>> sunxi is pretty generic ARMv7-class in that regard, but double-checking
> >>>>> is surely better.
> >>>>
> >>>> armv7 does not mean a particular timer. Cortex A9 or cortex A15 do,
> >>>> but different ones, and Cortex A8 does not for instance. The
> >>>> processor we are talking about is probably not a cortex A9 since on
> >>>> I-pipe, there is no timer or tsc defined on A9 when booting in UP
> >>>> mode (and GP Orcullo is booting in UP mode). So my question is not
> >>>> about "double-checking", it is rather the first check.
> >>>
> >>> The A20 is a dual-core Cortex A7.
> >>
> >> Strange that GP Orcullo is not running the kernel in SMP mode then.
> > 
> > The A20 uses PSCI to implement its SMP ops, which requires some
> > cooperation from the bootloader. Maybe he just has a too ancient
> > bootloader.
> 
> Recent upstream U-boot is a must, of course. I think the upstream kernel
> never supported SMP without PSCI, and the now obsolete sunxi U-boot was
> lacking that feature.

Exactly.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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